title: Time-trends and circumstances surrounding ankle injuries in men's professional football: an 11-year follow-up of the UEFA Champions League injury study.
abstract: BACKGROUND
  Ankle injury is common in football, but the circumstances surrounding them are not well characterised.
  
  
  OBJECTIVE
  To investigate the rates, especially time-trends, and circumstances of ankle injuries in male professional football.
  
  
  METHODS
  27 European clubs with 1743 players were followed prospectively between 2001/2002 and 2011/2012. Time loss injuries and individual-player exposure during training sessions and matches were recorded. Injury rate was defined as the number of injuries/1000 h.
  
  
  RESULTS
  A total of 1080 ankle injuries were recorded (13% of all injuries) with lateral ligament ankle sprain being the most common injury subtype (51% of all ankle injuries). The rates of ankle injury and ankle sprain were 1/1000 h and 0.7/1000 h, respectively. The ankle sprain rate declined slightly over time during the 11-year study period (on average 3.1%/season) with a statistically significant seasonal trend (p=0.041). Foul play according to the referee was involved in 40% of the match-related ankle sprains. Syndesmotic sprains and ankle impingement were uncommon causes of time loss (3% each of all ankle injuries).
  
  
  CONCLUSIONS
  Lateral ligament ankle sprain constituted half of all ankle injuries in male professional football, whereas ankle impingement syndromes were uncommon. The ankle sprain rate decreased slightly over time, but many ankle sprains were associated with foul play. Our data extend the body of literature that provides football policy makers with a foundation to review existing rules and their enforcement.
authors.affiliation: Division of Community Medicine, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden. markus.walden@telia.com
authors.forename: Markus
authors.initials: M
authors.lastname: Waldén
authors.forename: Martin
authors.initials: M
authors.lastname: Hägglund
authors.forename: Jan
authors.initials: J
authors.lastname: Ekstrand
mesh_terms: D000041:Absenteeism; D016512:Ankle Injuries / Q000453:epidemiology* / Q000209:etiology; D005060:Europe / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D017844:Lateral Ligament, Ankle / Q000293:injuries; D008297:Male; D011446:Prospective Studies; D012008:Recurrence; D012916:Soccer / Q000293:injuries*; D013180:Sprains and Strains / Q000453:epidemiology* / Q000209:etiology; D013997:Time Factors